BUSINESS CYCLES: The recurring expansions and contractions of the national economy (usually measured by real gross domestic product). A complete cycle typically lasts from three to five years, but could last ten years or more. It is divided into four phases -- expansion, peak, contraction, and trough. Unemployment inevitably rises during contractions and inflation tends to worsen during expansions. To avoid the inflation and unemployment problems of business cycles, the federal government frequently undertakes various fiscal and monetary policies. See also | real gross domestic product | economy | full-employment production | resources | aggregate expenditures | contraction | recession | expansion | peak | trough | recovery | unemployment | inflation | fiscal policy | monetary policy | business cycle phases | circular flow | business cycle measurement | economic indicators |